I submitted the 4th version of
"On Controlled Assembly Maps". I thank the referee for carefully reading the manuscript
and giving me various suggestions and comments. >> [final version]
-- Dec. 25, 2012.

I may attend the following meetings and conferences in the academic year 2012/2013:

There will be a conference "Topology, Geometry, Dynamics" dedicated to the 90th anniversary of the birthday of
Vladimir Rokhlin (1919 - 1984) from January 11th through 16th in Saint Petersburg, Russia.
I do not think I will be able to attend it.
-- Nov. 6, 2009.

While some of my senior seminar students were studying Pick's theorem,
one of them reported on
Nukaga's theorem
which gives a method to compute the area of lattice polygons in a different way.
Here
is an English translation of a report by my students.
-- February 28, 2009.

Five of my senior seminar students read "Topology of Surfaces,
Knots and Manifolds" by S. C. Carlson and compiled the solutions
to the end-of-chapter problems as a senior thesis
[presentation pdf files:
#1#2,
#3,
#4,
#5 (in Japanese)].
The other two students studied vector fields on surfaces and wrote
a joint thesis "Vector Fields
and Hair Whirls" [pdf for
presentation] (in Japanese).
The main result is an extension
of the Poincare-Hopf Theorem for continuous vector fields on a compact surface
that have only isoated singular points in the interior.
When they are almost finishing the thesis, we learned about the work of M. Morse
on general vector fields with singularities away from the boundary.
Since it was too late to incorporate the stuff into the thesis, they only
mentioned Morse's formula in a remark. I discussed Morse's formula
("the law of vector fields") with H. Kamae (one of the students), and
we now think the formula can be extended to the case where the vector field V
is allowed to have isolated singular points also on the boundary:
This is true at least when the "boundary" of V has only isolated singular points.
The idea is to consider the double DX of the manifold X (i.e. the boundary
of Xx[-1,1]) and define the "double" DV of V to be equal to
V on the two copies of X and to be the obvious homotopy
on the rest. Note that we have the "boundary" of V in the middle.
Please let me know if this is already known to people.
-- March 2, 2008 (modified on March 5, 2008)
"Local indices of a vector field at an isolated zero on the boundary"
(arXiv: math.GT.0803.2139)
[the 2nd version--March 19, 2008]
[errata--updated on March 21, 2008]
[the 3rd version--April 3, 2008]
[the 4th version--April 6, 2008]

I corrected several errors and added some ingredients to
the presentation pdf file
of the lectures at Kinosaki.
-- Mar. 19, 2007.

My senior seminar students wrote
a joint thesis "Knots and Bands"
(in Japanese). The main result is :
let M be a Moebius band in the 3-space. Cut M along the center line
and obtain an annulus A. The center line of A is a trivial knot if only if
the center line of M is a trivial knot and M is half twisted.
Here is a pdf file they used for the presentation:
[pdf] (in Japanese).
-- Mar. 1, 2007.

Lewis C. Tiffany Garden Museum
in Matsue will be closed at the end of March.
I visited the museum when it was in Nagoya, and was very impressed.
When I moved to Okayama, I was very happy because the museum is rather
close to Okayama. I thought I could go there anytime, and did not visit the
museum after moving to Okayama. I will visit the museum in March.
-- Feb. 27, 2007.

I will give three 90-minute lectures
(pdf)
on surgery theory at
Kinosaki School / Topology in the 60's (March 12 -- 15, 2007).
Well, I really do not know much about the 60's, since I was an elementary/middle
school student back then.
-- Jan. 18, 2007.

Sayuri Haraguchi --
the wife of Masatake Kuranishi of Columbia University -- is a daughter
of a psychologist Tsuruko Haraguchi, who is the first Japanese woman
getting a Ph.D. A documentary film of Haraguchi is being shot now.
Kuranishi and his wife will appear in the film.
See the diary of the director Etsuko Izumi which appeared
in the recent issue of
CinemaJournal magazine.
-- Dec. 22, 2006.
[Official Site : http://www.sepia.dti.ne.jp/tess/]

Two films featuring Xia Yu will be shown at the
China-Shanghai Film Festival in Tokyo this month.
The details can be found at
the official site.
-- Dec. 5, 2006.

Dusan Repovs will give a talk "Topologist sine curve and its many
applications" at Okayama University of Science on January 12, 2007.
[abstract]
--Dec. 4, 2006.

An international conference on topology
Intelligence of Low Dimensional Topology
will be held at Hiroshima University, July 22 -- July 26.
I will probably attend the conference from July 23 to July 25.
-- May 12, 2006.

Hegenbarth and Repovs showed that surgery obstruction theory works
in the topological category for certain 4-manifolds related to torus knots
in "Applications of controlled surgery in dimension 4: examples".
It seems their argument also works for hyperbolic knots, and I wrote
a short note "Hyperbolic knots and 4-dimensional surgery".
>>hyperbolic.pdf
-- Jan. 15, 2006.

Prof. Dusan Repovs
(Univ. of Ljubljana, Slovenia) will give a talk
titled "Homology 3- and 4-manifolds: A survey" at Okayama University of Science
on January 16, 2006, 4:30--6:00pm in the seminar room on the 5th floor of Building 20.
[abstract]-- Nov. 29, 2005

Andrew Ranicki wrote to me about a TV movie titled "Hawking", in which
Roger Penrose convinces Hawking of the value of topology. Visit Andrew's
Surgery Bits and Pieces
page for more information.
--Oct. 11, 2005

Lots of people show a list of their mathematical ancestors on their
web pages. So I made one myself : my ancestors,
consulting The Mathematics Genealogy Project site. According to this site, Hilbert has 11462 descendants.
On the other hand, Poincare has only one descendant [two descendents as of June 19, 2007]!
I wonder what is the difference between them.
--Oct. 4, 2005

A revision of Quinn's math.KT/0402396 paper was posted on September 19th.
It omits material included in math.KT/0509294.
It seems it is not in the final form yet, since section 7 is still missing.
--Sept. 21, 2005

The Proceedings of the 2003 Oberwolfach Mini-Workshop "Exotic Homology Manifolds"
is now almost in the final form. A pdf file can be obtained at Andrew Ranicki's
Books Page.
-- August 7, 2005

I have been studying the new paper by F. Quinn
"Homology manifolds and 4-dimensional surgery" (math.GT/0504258) ,
but I learned today that
"April 2005 version withdrawn May 2005 due to an error in the even-dimensional part of the proof"!!!
-- May 11, 2005